Roman Numerals Converter Calculator
Convert between Arabic numbers and Roman numerals instantly. Learn the ancient Roman numeral system with step-by-step conversion explanations.
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About
Our Roman Numerals Converter helps you convert between modern Arabic numbers and ancient Roman numerals, with educational explanations of the conversion process and historical context.
Why Choose
Bidirectional conversion, step-by-step explanations, multiple numeral styles, educational content, validation checks, and support for numbers 1-3999 with historical context.
Features
Number to Roman conversion, Roman to number conversion, conversion step breakdown, numeral style options, validation, and comprehensive Roman numeral chart reference.
Benefits
Learn ancient numbering systems, understand historical documents, complete educational assignments, verify numeral accuracy, and explore mathematical history and culture.
Choose Direction
Select whether you want to convert from Arabic numbers to Roman numerals or from Roman numerals to Arabic numbers using the toggle buttons.
Enter Input
Type your number (1-3999) or Roman numeral. The calculator validates your input and provides real-time feedback for accuracy.
Get Results
View the conversion result with step-by-step breakdown, validation status, and additional information about the number or numeral.
Frequently Asked Questions - Roman Numerals Converter
The seven basic Roman numeral symbols are: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). These symbols are combined using addition and subtraction rules to represent all numbers from 1 to 3999 in standard notation.
Subtraction rules: I can be subtracted from V and X (IV=4, IX=9). X can be subtracted from L and C (XL=40, XC=90). C can be subtracted from D and M (CD=400, CM=900). Only one smaller numeral can precede a larger one, and only powers of 10 can be subtracted.
Standard Roman numerals can't exceed 3999 because you can only repeat a symbol three times (MMM = 3000). Numbers 4000+ would require MMMM, which violates Roman numeral rules. Larger numbers used overlines (vinculum) or different notation systems in ancient times.
Additive notation only adds symbols (IIII for 4), while subtractive notation uses subtraction rules (IV for 4). Classical Roman inscriptions often used additive notation, but subtractive notation became standard in medieval times and is used today for efficiency.
Read Roman numerals from left to right. Start with the largest values: count Ms (1000s), then hundreds (CM, CD, D, C), then tens (XC, XL, L, X), then units (IX, IV, V, I). Add them together, applying subtraction rules when a smaller numeral precedes a larger one.